<i>Dioscorea japonica</i> extract down-regulates prostaglandin E<sub>2</sub> synthetic pathway and induces apoptosis in lung cancer cells
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- Suzuki-Yamamoto Toshiko
- Department of Nutritional Science, Okayama Prefectural University
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- Tanaka Sayuri
- Department of Nutritional Science, Okayama Prefectural University
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- Tsukayama Izumi
- Department of Nutritional Science, Okayama Prefectural University
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- Takafuji Miki
- Department of Nutritional Science, Okayama Prefectural University
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- Hanada Takae
- Department of Nutritional Science, Okayama Prefectural University
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- Arakawa Toshiya
- Department of Biochemistry, School of Dentistry, Health Sciences University of Hokkaido
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- Kawakami Yuki
- Department of Nutritional Science, Okayama Prefectural University
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- Kimoto Masumi
- Department of Nutritional Science, Okayama Prefectural University
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- Takahashi Yoshitaka
- Department of Nutritional Science, Okayama Prefectural University
Bibliographic Information
- Other Title
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- Dioscorea japonica extract down-regulates prostaglandin E2 synthetic pathway and induces apoptosis in lung cancer cells
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Abstract
Prostaglandin E2 plays a role in an array of pathophysiological responses, including inflammation, carcinogenesis and so on. Prostaglandin E2 is synthesized from arachidonic acid by the enzymes cyclooxygenase and prostaglandin E synthase. In some pathological conditions, the isozymes cyclooxygenase-2 and microsomal prostaglandin E synthase-1 are transiently induced, leading to prostaglandin E2 overproduction. The present study showed that Dioscorea japonica extract suppresses mRNA expression of cyclooxygenase-2 and microsomal prostaglandin E synthase-1 in human non-small-cell lung carcinoma A549 cells in a dose-dependent manner. The suppressive effects of Dioscorea japonica extract on the expression of cyclooxygenase-2 and microsomal prostaglandin E synthase-1 were confirmed by Western blotting, cyclooxygenase activity and prostaglandin E2 production. Dioscorea japonica extract induced the translocation of nuclear factor-κB from the nucleus to the cytosol and inhibited the activity of the cyclooxygenase-2 promoter. Furthermore Dioscorea japonica extract suppressed the expression of the anti-apoptotic factor B-cell chronic lymphocytic leukemia/lymphoma 2 and enhanced apoptotic terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling-positive intensity in A549 cells. These results suggest that Dioscorea japonica extract suppresses the expression of cyclooxygenase-2 and microsomal prostaglandin E synthase-1, with the regulation of the transcriptional activity of cyclooxygenase-2, and induces apoptosis in cancer cells. Thus, Dioscorea japonica may contribute to the prevention of prostaglandin E2-mediated pathophysiological responses such as carcinogenesis and inflammation.
Journal
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- Journal of Clinical Biochemistry and Nutrition
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Journal of Clinical Biochemistry and Nutrition 55 (3), 162-167, 2014
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